The present invention relates to the field of quaternary ammonium compounds (xe2x80x9cquatsxe2x80x9d) and, in particular, their use in additives for personal care products such as shampoos, conditioners, skin care products and the like.
Human hair contains a thin protective fatty layer of an ante-iso fatty acid, 18-methyl eicosanoic acid (18-MEA), covalently bound to the cuticle. Chemical or mechanical damage to the hair removes portions of this fatty layer making the hair less manageable, less healthy looking and more susceptible to environmental stresses. In the treatment of hair, it is desirable to replenish these ante-iso fatty acids, particularly 18-MEA.
18-MEA is relatively rare in nature and is found in small amounts in materials such as lanolin. Lanolin contains a mixture of fatty acids, including amongst other things, ante-iso fatty acids, as well as hydroxy fatty acids, iso-hydroxy fatty acids, iso fatty acids and unsubstituted fatty acids. U.S. Pat. No. 4,069,347, issuing to McCarthy et al., discloses compositions of quat derivatives of fatty acids derived from lanolin. These lanolin-derived quats are described as being useful, when combined with specific branched-diols, in the preparation of clear cosmetic formulations. These include shampoos and clear hair rinse formulations.
In one aspect, the present invention relates to quats derived from either fatty acid compounds consisting essentially of ante-iso fatty acids or fatty acid mixtures enriched in ante-iso fatty acids.
These quats impart desirable properties when used as additives to personal care products including hair grooming preparations and skin care products. Personal care products which include an additive of quats consisting essentially of ante-iso fatty acids or comprising fatty acid mixtures enriched in ante-iso fatty acid content are also contemplated.
A number of new discoveries have been made with important consequences for personal care products. First, it has been discovered that of all the various components contained in lanolin, it is the ante-iso fatty acids which, when quaternized, have the most profound effect upon the health and manageability of hair and/or skin. It has also been discovered that additives which consist essentially of quats of one or more ante-iso fatty acids, without significant quantities (greater than 5%) of the quats of other fatty acid species traditionally found in lanolin, yield superior personal care products. Of course, the personal care products containing these quat based additives can, and often will, include other fatty acids and fatty acid quats in varying amounts for other reasons.
It has further been discovered that of these ante-iso fatty acids, 18-MEA (having a C-21 chain), is particularly useful and provides dramatically improved results over, for example, quaternized lanolin acids derived directly from lanolin. Thus, additives containing a relatively large proportion of 18-MEA when compared to, for example, lanolin are extremely effective additions to personal care products.
However, these ante-iso fatty acids and, in particular, 18-MEA, are not typically found in nature in large quantities. These materials are also generally not found in sources from which they can be easily extracted in large quantities. U.S. Pat. No. 5,476,649, issuing to Naito et al., the text of which is hereby incorporated by reference, discloses various synthetic methods for preparation of ante-iso acids. The various synthetic preparations disclosed all call for the use of reagents and solvents such as benzene, xylene, triphenylphosphine, phosphorous tribromide, etc., that create handling and disposal difficulties due to their toxicity. These manufacturing procedures are difficult, time consuming, costly and solvent intensive. Still, where available, additives produced almost exclusively from ante-iso fatty acid quats, particularly those with fatty acid chains longer than 15 carbon atoms, and more preferably those made with 18-MEA, are desirable.
While it is desirable to make and use additives of quats made almost exclusively from ante-iso fatty acids, it has also been unexpectedly found that significant improvements in hair and skin care products, make-up, cosmetics and the like, can be obtained without the need for formulations limited to substantially only these quats. Desirable and unexpected results are also obtained by using quats resulting from mixtures of ante-iso acids with other fatty acid species, such as the mixtures that are found in lanolin, so long as the content of the ante-iso acids, and accordingly, the content of their corresponding quats, is enriched relative to lanolin. This can be done by, for example, processing lanolin acids, such as those disclosed in McCarthy et al., U.S. Pat. No. 4,069,347, the text of which is incorporated herein by reference, and enriching them by the addition of more ante-iso acid quats such as those produced in Naito et al. A relative increase in the content of ante-iso fatty acids can also be accomplished by removing some quantity of less desirable fatty acid species, such as by concentration techniques like molecular distillation. This approach can be accomplished without the use of solvents. When concentrating, for example, lanolin acids, it is most preferred to use techniques which result in a decrease in the relative proportion of iso-hydroxy fatty acids and hydroxy fatty acids thereby enriching the relative proportion of the ante-iso fatty acids.
It has also been found that many quats produced from ante-iso enriched mixtures are compatible with anionic surfactants. For the purposes of this application, xe2x80x9ccompatible with anionic surfactantsxe2x80x9d means that a clear solution, one without significant precipitation or turbidity, results once the quat is mixed with the surfactant. This is surprising since it was previously thought that with standard lanolin acid quats, such as those described in McCarthy et al., it was the presence of significant amounts of hydroxy fatty acid quats that made them anionic surfactant compatible. Since in accordance with the present invention, the iso-hydroxy fatty acids and the hydroxy fatty acids are generally removed, or their relative proportions reduced, it is completely unexpected to see continued anionic surfactant compatibility.
Ante-iso acids conform to the following formula: 
where xe2x80x9czxe2x80x9d can be any positive whole number, and R is an alkyl group, substituted or un-substituted, straight chain or branched, saturated or unsaturated. This alkyl group may be substituted or unsubstituted.
Hydroxy fatty acids include at least one xe2x80x94OH group attached to the fatty acid chain. Iso fatty acids are similar to ante-iso fatty acids except that the attached alkyl group is located closer to the carbonyl group, usually on the next adjacent carbon.
The ante-iso acids used to produce the quat compounds in accordance with the present invention can be individually essentially pure (either all ante-iso fatty acids or a mixture of substantially only ante-iso fatty acids) or part of a fatty acid mixture that is generally comprised of acids illustrated, by example in Table I.
In the present application, hydroxy fatty acids or iso-hydroxy fatty acids are preferably minimized to levels at least about 10% lower than that typically found in lanolin and more preferably substantially eliminated. Additionally, the ante-iso fatty acids are preferably kept at levels greater than those typically found in lanolin, more preferably at levels at least about 10% greater than those typically found in lanolin.
A more preferred fatty acid mixture useful to produce quats in accordance with the present invention has a fatty acid content distribution as shown in Table II below.
For purposes of comparison, a typical distribution of the fatty acids contained in lanolin acids is shown in Table III below.
As is evident from Table III, the fatty acid distribution of typical lanolin acids contains greater than 35% hydroxy fatty acids and iso-hydroxy fatty acids. It is desirable to reduce or eliminate these hydroxy fatty acid and iso-hydroxy fatty acid species, thereby increasing the concentration of the ante-iso fatty acids. Alternatively, either other fatty acid species can be eliminated or additional ante-iso fatty acids can be added to enrich the relative proportion of ante-iso fatty acids.
The quaternary compounds in accordance with the present invention may, for example, have the formula (I): 
where R is 
R3 is an alkyl group, straight chain or branched, saturated or unsaturated, z may vary from 0 to 30; B is any organic group connecting group R to the quaternized nitrogen; D is any organic group attached to the quaternized nitrogen in any manner; R1 and R2, are each independently alkyl or alkoxy quaternizing group, same or different; Yxe2x88x92 is a counter ion. Preferably, R is an alkyl group having from 8 to 30 carbon atoms; z ranges from 3 to 25, more preferably z ranges from 5 to 22, most preferably z is 16; R3 has up to 12 carbon atoms, more preferably, from 1 to 6 carbon atoms, most preferably R3 is methyl. Preferably, B and D contains C, H, N, and O atoms; Yxe2x88x92 is halogen-, sulfur- or nitrogen-containing anion; most preferably halogen, sulfate, sulfite, sulfide or nitro anion.
The specific quaternary compounds in accordance with the invention may, for example, have the formula (II): 
where at least one of R is 
R3 is an alkyl group, straight chain or branched, saturated or unsaturated, z may vary from 0 to 30; each A1 and A2, same or different, are independently alkoxy or lower alkyl; z may vary from 0 to 30; R4 and R5 are alkyl groups, same or different; n may range from 0 to 10, x may range from 1 to 6; Yxe2x88x92 are counter ions; if only one R is 
then another R is an alkyl group, straight chain or branched, aromatic or aliphatic, saturated or unsaturated, substituted or un-substituted, having up to 30 carbon atoms. Preferably, when R is 
R has from 8 to 30 carbon atoms, preferably z ranges from 3 to 25, more preferably z ranges from 5 to 22, most preferably z is 16; if only one R is 
then another R is preferably an aliphatic alkyl group having 12 to 24 carbon atoms, more preferably 14 to 22 carbon atoms; R4 and R5 are independently lower alkyl groups, more preferably methyl or ethyl, most preferably R4 and R5 are both methyl; A1 and A2 are each independently ethoxy, polyethoxy, propoxy, methyl or lower alkyl having from 1 to 6 carbon atoms; R3 is a alkyl group having up to 12 carbon atoms, more preferably from 1 to 6 carbon atoms, most preferably methyl; Yxe2x88x92 are halogen-, sulfur- or nitrogen-containing anions; most preferably halogens, sulfates, sulfites, sulfides, or nitro anions. Most preferably R is derived from 18-methyl eicosanoic acid, i.e., R3 is methyl, and z is 16.
Other specific quaternary compounds in accordance with the invention may also, for example, have the formula (III): 
where R groups is 
R3 is an alkyl group, straight chain or branched, saturated or unsaturated, z may vary from 0 to 30; R6 and R7, same or different, are each independently aromatic or aliphatic alkyl group, straight chain or branched, saturated or unsaturated, or an alkoxy group; x ranges from 1 to 6; A is alkoxy or lower alkyl; Yxe2x88x92 is a counter ion. Preferably, R is an alkyl group having from 8 to 30 carbon atoms; z ranges from 3 to 25, more preferably z ranges from 5 to 22, most preferably z is 16; R3 is a alkyl group having up to 12 carbon atoms, more preferably from 1 to 6 carbon atoms, most preferably methyl; R6 and R7, same or different, are each independently aromatic or aliphatic alkyl group having from 1 to 8 carbon atoms, or ethoxy, polyethoxy, propoxy or polypropoxy group; A is ethoxy, polyethoxy, propoxy or polypropoxy, or lower alkyl having 1 to 6 carbon atoms; Yxe2x88x92 is halogen-, sulfur- or nitrogen-containing anions; most preferably, halogen, sulfate, sulfite, sulfide, or nitro anion. Most preferably R is derived from 18-methyl eicosanoic acid, i.e., R3 is methyl, and z is 16.
The quats in accordance with the present invention can be made by any technique such as, without limitation, the procedures described in U.S. patent applin. Ser. No. 09/409,203 (xe2x80x9c""203 applicationxe2x80x9d), by inventors Pereira and Barinova, or U.S. patent applin. Ser. No. 09/409,204 (xe2x80x9c""204 applicationxe2x80x9d), by inventors Pereira and Nikolopolous. These two applications were filed on Sep. 30, 1999 and are assigned to the assignee of the present application. The contents of these applications are hereby incorporated by reference herein.
The ""203 application describes an exemplary synthesis in which the quats are prepared by first reacting fatty acid and diethylenetriamine (DETA) or similar amine species. The product should then be cooled and ethylene oxide should be added. After the ethylene oxide has reacted sufficiently, the batch should be further cooled and then quaternized in the presence of propylene glycol, butylene glycol, isopropyl alcohol and the like with dimethyl sulfate, methyl chloride, benzyl chloride and the like or any other quaternizing agent generally known to those skilled in the art.
The ""204 application describes an exemplary synthesis in which the quats are prepared by reacting fatty acids, oils, triglycerides, or mixtures thereof, with dialkyl amines such as gamma dimethylamino-propylamine (DMAPA), gamma diethylamino-propylamine (DEAPA) using an alkaline catalyst such as sodium hydroxide to produce an amidoamine. The appropriate amidoamine is then quaternized with either ethylene chlorohydrin or ethylene bromohydrin in a solvent mixture such as water and propylene glycol.
As discussed above, various amine species are useful to produce quats in accordance with the present invention including, without limitation, dialkyl amines such as diethylenetriamine (DETA), gamma dimethylamino-propylamine (DMAPA), gamma diethylamino-propylamine (DEAPA) or triethylene tetraamine (TETA).
These quats traditionally are present with counter ions. Counter ions can include any known to be useful with quaternized amino amines such as, for example, and without limitation, chlorine, bromine, etc.
Quats can also be formulated in a varying range of cationic activities. The cationic activity of a quat is used to measure the content of the quats disbursed or dissolved in the solvent in a percent by weight basis. Thus, a quat that has 50% cationic activity is provided in a 50% weight ratio to the solvent. Generally, it is preferred that a higher percent cationic activity be provided. This can be done by diluting or concentrating solutions of the quats prepared in accordance with the present invention as is known in the art. While water can be used as a carrier or solvent, other useful carriers include glycols or polyglycols, fatty alcohols, alkoxy alcohols, or any mixtures of these solvents. Other useful solvent mixtures can be found in U.S. patent applin. Ser. No. 09/438,631 by inventors Barinova, Nikolopolous and Pereira. This application was filed on Nov. 12, 1999, is assigned to the assignee of the present application, and is hereby incorporated by reference herein.
It is also preferable that the resulting quats be flakeable or pastillatable. Whether a formulation is flakeable is measured by pouring a relatively thin film ({fraction (1/16)}xe2x80x3-xe2x85x9xe2x80x3) of a heated composition onto a metal sheet and allowing it to cool. The cooled film is then xe2x80x9ccrumbledxe2x80x9d or xe2x80x9cscrapedxe2x80x9d into small flakes by any type of mechanical process. Thus, a successful composition must possess two properties. First, the composition must possess the property of being easily poured onto the sheet, thus forming a thin film. Second, once the composition is allowed to cool, it must break into flakes after crumpling or scraping. These flakes are consequently easily stored and re-melted as necessary.
Pastillation is a process in which small amounts of the desired formulation are dispensed into pastilles. These pastilles are then allowed to cool, forming a product, which is in solid form, but easily returned to liquid state. Whether a formulation is capable of pastillation is measurable by distributing small amounts of the heated formulation into pastilles. These pastilles are then allowed to cool. The pastilles must be easily melted without tremendous amounts of heat, preferably below the boiling point of water.
In one aspect of the present invention, the ante-iso fatty acid content in quat mixtures is enriched by adding relatively pure ante-iso fatty acids to an existing mixture. Where enrichment of the ante-iso fatty acid content is accomplished by adding ante-iso fatty acids to an existing mixture of fatty acid species, such as lanolin, the resulting mixture will contain hydroxy fatty acids; however, their relative percentage will be accordingly reduced. In this context, xe2x80x9cenrichedxe2x80x9d generally should be construed as containing an amount greater than the amount of ante-iso fatty acids contained in lanolin, and more preferably about 10% greater than the amount of ante-iso fatty acids contained in comparable lanolin mixtures and compositions. An additive for personal care products including hair care products (shampoos and conditioners) skin care products and cosmetics containing quats produced from these ante-iso enriched fatty acid mixtures is also an aspect of the invention.
In another aspect of the present invention there is provided an additive for hair care, cosmetic and skin care products which consists essentially of quaternary compounds of ante-iso fatty acids. In this context, the term xe2x80x9cconsisting essentially ofxe2x80x9d should be construed as excluding other fatty acid species commonly found in lanolin such as hydroxy fatty acids, unsubstituted or normal fatty acids and iso fatty acids. These should be present, if at all, in as small an amount as possible and, preferably, in less than a total of 15% by weight of the additive.
Another aspect of the present invention is an additive for such personal care products consisting essentially of 18-MEA. xe2x80x9cConsisting essentially ofxe2x80x9d in this context allows for the presence of up to 20% of other ante-iso fatty acid quats and up to 15% of quats based on hydroxy fatty acids, unsubstituted fatty acids and/or iso fatty acids. Personal care products containing any of the above additives are also specifically contemplated.
Finally, the quats and in particular, the additives produced from the quats in accordance with the present invention are preferably compatible with anionic surfactants. It is to be understood that not all of these quats are compatible with anionic surfactants. For example, certain dialkyl quats disclosed in the ""204 application are not compatible. Generally those dialkyl quats without free hydroxy groups attached to the fatty acids used to quarternize the N atom of the amide will not be compatible with anionic surfactants. Additionally, benzyl quats in accordance with the ""203 application are also generally not compatible with anionic surfactants.
In addition to the quats and solvents, additives for personal care products in accordance with the present invention can include other quat formulations such as those described in the ""203 and ""204 application (resulting in hybrid blends), fatty alcohols with C12-C22 chains (promoting flakeability), glycols (for handling), as well as protein additives. The resulting quat formulations and resulting blends can potentially be used in a variety of skin and hair care products including, but not limited to, ointments, lotions, anti-bacterial products, shampoos, conditioners, shaving preparations, etc.
The quat additives of the present invention are added to these personal care products, generally in an amount sufficient to provide a cationic activity (on an active basis) of between about 0.5% to about 10% by weight. These quat additives are useful in products such as shampoos, conditioners, skin care products and the like.